This is the moment a relaxing cruise was reduced to bloody chaos as two warring families began beating each other after one man stepped on another's flip-flop.

The Carnival Legend ship was on a 10-day South Pacific cruise when savage fist fights broke out as it was 220km off Jervis Bay, Australia, around 1am on Friday.

One witness, named only as Zac, said the brawl started after two men tangled feet, leading to a bitter exchange of words between two family groups.

That then escalated into a brawl, with Zac accusing security of escalating the situation before piling into the foray with vicious kicks and punches. 

He told 3AW: 'This is all over a thong [flip-flop] - not a foot - a thong being stepped on and being instantly apologised for.' 

Footage of one of the fights shows two men being bundled to the floor by dozens of security guards who punch and kick the pair in an attempt to separate them.

Two women are also pinned down after they become involved in the massive brawl which left other passengers so fearful they barricaded themselves in their rooms.

Police were called as the vessel docked at Eden and 23 members of the same family - including six men and three teenage boys - were detained. 

Police, who are now investigating the fights, said the family was transported to Canberra where other travel arrangements were made. 

Jennifer Vandekreeke, vice-president of Carnival Cruises Australia, said the company called police as the family group were 'violent and disruptive.' 

One man, named Michael, was brutally kicked while he was pinned to the ground and received cuts and bruising to his face, back and legs.

Chaotic scenes were captured as security guards could be seen repeatedly kicking a passenger after he falls to the ground before another staff member pinned him down.

One man could be heard saying, 'Don't hit my girlfriend' as a security guard pretended  to lunge at a woman.  

A woman could also be heard saying: 'Do not touch him'

At one point during the footage a member of cruise staff attempts to stop the person behind the camera from filming the incident.  

Michael revealed the extent of his brutal injuries in harrowing photographs shared with 3AW.

Witnesses claim as many as 30 feuding passengers were involved in the violent on board clashes which occurred in common areas in front of families. 

'We are so scared after witnessing a traumatic experience with yet again the same offenders. It was a bloodbath,' the anonymous guest said. 

'We will not be leaving our cabins and are truly scared for our safety and what could happen in the next 24 hours.'

Some guests have even described their ocean holiday as the 'cruise from hell'. 

David Barkho, the father of a 20-year-old man caught up in the violence, told 3AW he received a frantic phone call from his injured son at 1am. 

'He said, "Please Dad, please, call the Federal Police",' Mr Barkho said.

'I could hear a lot of screaming, crying in the background.'

Mr Barkho also alleges cruise security staff are attempting to destroy images and footage from the incident.

'He (George) said, "The security came in and took his phone, and deleted a lot of images",' he added.

Passenger Kellie Petersen told 3AW it was 27 people from one big 'family group' inciting the violence.

'We have been told to watch our backs by this group,' she said.

'They fought in front of my children in the pool... five of them surrounded my husband.'

 The cruise liner has made an unexpected stop at a port in Eden, New South Wales, before it heads to Melbourne tomorrow.  

NSW Police confirmed to Daily Mail Australia that a police operation is underway at the port on the NSW south coast.

Police received reports of passengers fighting on board the Carnival Legend and a number of people are expected to be removed from the vessel.  

Read more on dailymail.co.uk.